This was a ‘start from scratch’ project, so Im using a SSC-32 Servo controller connected via a blueSMiRF bluetooth connection to my computer running a
kinematic engine programmed by myself allowing for the usual 3-degrees of body rotations and 3-degrees of body translations. Tripod and Wave gaits.
The programme also includes the ability to enter an attack pose and then have individual control of the front legs with the analogue sticks on the controller.
The legs were rapid prototyped for me at my university and the body has been through a few designs but was always made using PVC foam and Polymorph.
The current version of hexi has a pan tilt head with a wireless 2.4G camera which I am programming in to allow face tracking.
The most recent addition is the controller has changed from a standard usb game pad to a Playstation 3 sixaxis controller and the ability to controller hexapod
using the accelerometers and gyroscopes
Now Ive finished with that project I am moving from 6 to 4 and im trying to build a quadruped using the same basic components. So far Im a day into construction
The basics of the code will be stolen from the hexapod program but the aim will be to create a more sophisticated locomotion and terrain adaption routines.
Can it be interfaced with the wireless module we use with the PS2? I assume the packets would change, but we could accommodate that. It would be nice to get a few more axis.
Also, some videos should be online soon, including the kid that burst into manic screams at the sight of our bots (you can clearly hear me chuckling!!)
The legs look awesome. I like the nice contours of the design and it reminds me of the A-Pod that used contours also which brings a bio look to the bots.
I wonder how strong the rapid-prototyped legs are? It’s interesting stuff. We had a Dimension machine for the mechanical guys at the last company I worked for, and one here as well. This company is so large, I don’t even know where the machine is! I’m not sure how well the ME’s would like an EE making hobby parts on their machine!
Finally got my new blueSMiRF so I could start reprogramming, adapting my hexapod code to work on a quad.
So far the kinematics are 80-90% complete.
I using input from a PS3 controller through my pc and bluetooth to the robot. I have control of the pitch and roll of the body using the controllers gyros. Body translations are done with the left analogue stick. Body Twist is controlled with the triggers R2 L2.
The last part of the clip shows the centre of gravity being shifted to allow the unloaded leg to be lifted.
Ive written the beginings of the walking/gait routines. They need some work to smooth out the motion and to allow the fully omnidirectional locomotion.
I am also going to experiment as to whether using body rotations to lean the body will reduce the amount of body translation required to shift the centre of gravity within the tripod. This should help the gait be more fluid.
Hi Alan, The controller Im using the standard Sony Playstation 3 controller, also called the Dualshock 3. I have not used Xans code before but I assume that, with a mod or two, it would be possible to integrate it as the controller.
Makes for an interesting gait! Will your 'bot walk successfully with less body translations? It appears that your legs are orientated in a symmetrical fashion, whereas I’m thinking I’ll experiment with a rather pronounced (mammalian) 2:1 (to be verified) aspect ratio.
Ah yes! Dualshock 3 does come up in Google, even at Amazon! I wonder if anyone has tried the LM XCVRs with the Dualshock 3?
USB, or Bluetooth? That wouldn’t matter for looping through a PC as I’ve considered, but it would require a Bluetooth XCVR (USB?) that could be connected to the BB2. a Wii controller might have similar requirements (it’s own specific XCVR).
